1. Field of the Invention
The present invention relates to a cable harness used in a vehicle and a water cutoff structure thereof.
2. Description of Related Art
There has been known a harness that bundles an electric wire for electrically connecting a sensor or an actuator provided in a vehicle to a control device, and an electric wire for supplying an electric power. A harness that communicates an inside of a passenger compartment of a vehicle with an outside thereof is passed through a hole of a body panel constituting a vehicle body and separating the inside of the passenger compartment from the outside thereof. A gap between the hole and the harness is closed by a grommet made of a flexible material such as rubber, so that water invasion from the gap into the passenger compartment is prevented.
The grommet has a hole through which the harness passes. In a case where a plurality of electric wires is bundled up, an outer circumference of the bundle becomes uneven due to respective outer shapes of the electric wires. In view of this, even if the grommet is flexible, an inner peripheral surface of the hole of the grommet may not sufficiently make close contact with the bundle of the electric wires. Japanese Patent Application Publication No. 2012-85387 (JP 2012-85387 A) describes a technique in which a water cutoff portion in which electric wires are buried is provided in a harness, and an inner peripheral surface of a hole of a grommet makes close contact with an outer peripheral surface of the water cutoff portion so as to prevent water from coming inside. The water cutoff portion is made of resin, so that gaps between the electric wires and gaps between the grommet and the electric wires are filled up with resin. The outer peripheral surface of the water cutoff portion does not have unevenness due to the electric wires, so that water cutoff performance with respect to the grommet is secured. Japanese Patent Application Publication No. 2012-231572 (JP 2012-231572 A) describes a technique in which a molten water-stopping agent is penetrated into gaps between electric wires, and then hardened so as to fill the gaps between the electric wires. Japanese Patent Application Publication No. 2012-165485 (JP 2012-165485 A) describes a technique in which a foaming liquid concentrate is injected between electric wires placed in a tubular portion of a grommet so as to foam in place, thereby filling gaps between the electric wires and gaps between the electric wires and the tubular potion with a water cutoff body.
In a case where a high-frequency current flows in electric wires, an electromagnetic shield may be performed by surrounding the electric wires with a braided wire so as to prevent an electromagnetic wave from being radiated from the electric wires. The braided wire is formed by weaving thin element wires, and there are small gaps between the element wires. It is difficult to penetrate resin into all of the gaps, and water may invade into a passenger compartment from some gaps that are not filled with the resin.